Fix/merge of pull request https://github.com/airportyh/testem/pull/56. Fixes tty not defined error.
Fix/merge of pull request https://github.com/airportyh/testem/pull/56. Fixes tty not defined error.

Addepar/testem,johanneswuerbach/testem,bradleylandis/testem,johanneswuerbach/testem,paulot/testem,Addepar/testem,johanneswuerbach/testem,fotinakis/testem,bradleylandis/testem,fotinakis/testem,Addepar/testem,testem/testem,fotinakis/testem,bradleylandis/testem,testem/testem,Addepar/testem,paulot/testem,paulot/testem,testem/testem